Gene Asp299Gly Research Articles

Association between SNP rs4986790 and COVID-19 infection severity among Baghdad patients

Introduction and Aim: COVID-19, an infectious disease caused by the SARS-CoV-2 coronavirus, is distinguished by the manifestation of severe acute respiratory syndrome. Toll-like receptors (TLRs) are signaling molecules that play crucial roles in the innate immune system through their recognition of pathogen-associated molecular patterns in diverse microorganisms, including coronaviruses. The primary aim of this research was to investigate the plausible association between the TLR4 gene Asp299Gly polymorphism and the degree of infection severity among individuals who contracted COVID-19 in Baghdad, Iraq. Materials and Methods: This cross-sectional prospective study was carried out in Baghdad to investigate the Asp299Gly polymorphism within the TLR4 gene in a cohort of 90 patients diagnosed with Covid-19. Out of the total number of patients, 45 individuals exhibited symptoms indicative of a moderate infection, while the remaining 45 patients presented with a severe illness. The Asp299Gly polymorphism was analyzed using polymerase chain reaction (PCR) technique and restriction fragment length polymorphism (RFLP). Results: Genotyping for the Asp299Gly polymorphism showed only one among the 90 (1.1%) Covid-19 patients tested to be positive. No significant association was seen between covid-19 severity and Asp299Gly (P = 0·31) polymorphism. Conclusion: Our study found no association between SNP rs4986790 of TLR4 gene and COVID-19 severity among Covid-19 patients in Baghdad city.

Evaluation of the Impact of Some Single-Nucleotide Gene Polymorphisms on the Development of Adenomatous Polyps of the Colon in Patients with Irritable Bowel Syndrome.

The number of cases of irritable bowel syndrome is growing worldwide, in which adenomatous polyps can develop as a result of microinflammation of the colonic epithelium. Our study was aimed at the identification of the possible effect of single-nucleotide polymorphisms on the risk of the development of irritable bowel syndrome-related colonic adenomatous polyps. The study involved 187 irritable bowel syndrome patients. The single-nucleotide polymorphisms were investigated by the polymerase chain reaction method and DNA was extracted with the phenol-chloroform: interleukin-1β gene-31C/T (rs1143627), -511C/T (rs16944); interleukin-6 gene-174G/C (rs1800795); interleukin-10 gene-592C/A (rs1800872), -819T/C (rs1800871), -1082A/G (rs1800896); Toll-like receptor-2 gene Arg753Gln (rs5743708); Toll-like receptor-4 gene Thr399ile (rs4986791), Asp299Gly (rs4986790); and metalloproteinase-9 gene-8202A/G (rs11697325). The study of polymorphic loci was checked for compliance with the Hardy- Weinberg equilibrium using Fisher's exact test along with the analyses of the frequency of alleles and the genotypes. The association of diseases with G allele Toll-like receptor-2 gene Arg753Gln (rs5743708) was revealed in irritable bowel syndrome patients with adenomatous polyps of the colon (P < .0006) and AG single-nucleotide polymorphisms s of Toll-like receptor-2 gene (χ2 = 12.78, P < .002); A allele had a protective effect. The AG genotype metalloproteinase-9 gene-8202A/G (rs11697325) polymorphism in irritable bowel syndrome patients with adenomatous polyps of the colon had a protective effect (P < .05). AA genotype interleukin-10 gene-1082A/G (rs1800896) polymorphism in the irritable bowel syndrome patient (χ2 = 33.97, 4.0E-8) can be considered as the risk for adenomatous polyps of the colon in irritable bowel syndrome. G allele Toll-like receptor-2 gene Arg753Gln (rs5743708) and AA genotype interleukin-10 gene-1082A/G (rs1800896) polymorphisms can be the marker of the emergence of adenomatous polyps of the colon concomitant with irritable bowel syndrome.

The role of Toll-like receptor 4 gene polymorphism in the development of organ dysfunction in patients with severe pneumonia associated with A/H1N1 influenza

The aim of the study. To identify the frequency of occurrence of TLR4 Asp299Gly (rs4986790) gene polymorphism and to establish its contribution to the development of organ dysfunction in patients with severe pneumonia associated with A/H1N1 influenza.Materials and methods. The study included 55 patients with severe pneumonia associated with A/H1N1 influenza. Inclusion criteria: severe pneumonia; consolidation/ground-glass syndrome according to chest X-ray/CT. Exclusion criteria: unstable hemodynamics; body mass index &gt; 30; diabetes mellitus; HIV; tuberculosis, oncopathology. Verification of the pathogen in the respiratory swab was carried out using PCR method: A/H1N1 influenza virus RNA was identified. The age of the patients was 47 [38; 62] years. Among all the patients the proportion of men was 47.8 %, of women – 52.2 %. Patients were divided into 2 groups: group 1 included patients with SOFA scale (Sequential Organ Failure Assessment) score ≥ 2 points; group 2 – patients with SOFA scale score ˂ 2 points. Gene SNPs were determined by PCR method using standard kits developed by Research and Production Company “Litekh” (Moscow). Amplification of the TLR4 gene fragments was carried out in a thermocycler Bis-M111 (Bis-N LLC, Novosibirsk). Genomic DNA isolated from whole blood leukocytes using the “DNA Express Blood” reagent was analyzed followed by an amplification reaction. The amplification product was detected in a 3% agarose gel.Results. Multiple organ dysfunction (SOFA scale score ≥ 2 points) in patients with severe pneumonia associated with A/H1N1 influenza was registered in 24 (43.6 %) cases. When analyzing the frequency of occurrence of the minor Gly allele, according to genetic models, the differences were established between patients of the groups 1 and 2 in codominant (p = 0.023; odds ratio (OR) – 8.82 (0.95–81.89)) and dominant (p = 0.005; OR = 12.35 (1.40–109.07)) models.Conclusion. Severe pneumonia associated with A/H1N1 influenza is accompanied by a high incidence of organ dysfunction. The risk of organ failure development is 2.1 times increased in patients with severe pneumonia with identified TLR4 Asp299Gly gene polymorphism, which probably requires further study.

Toll-Like Receptor-4 Gene (Asp299Gly) polymorphism in allergic conjunctivitis

Allergic conjunctivitis (AC) is an allergic reaction that causes inflammation of the conjunctiva. Toll-like receptors (TLRs) are essential innate immune receptors that contribute to developing various allergic diseases. This case-control study aims to determine the correlation between TLR-4 gene (Asp299Gly) polymorphism and AC incidence and severity. The study included 70 AC patients and 70 non-allergic controls. All included subjects were subjected to a skin prick test, total immunoglobulin E (IgE) measurement, and TLR-4 gene (Asp299Gly) polymorphism detection by PCR restriction fragment length polymorphism (PCR-RFLP) technique. AC patients had significantly higher total IgE levels than controls (P ≤ 0.001). The frequency of the wild-type AA and heterozygous AG genotype were significantly lower in AC patients compared to controls (60 % vs. 80 % and 8.6% vs. 12.9 %, respectively). In contrast, the homozygous mutant GG genotype was significantly more prevalent among AC patients than controls (31.4 % vs. 7.1 %). Furthermore, the wild AA genotype was strongly associated with mild disease (68.2%); nonetheless, the homozygous mutant GG genotype was linked to severe disease (53.8%). The heterozygous AG genotype was only found in moderate AC patients (17.1%). AC patients with the mutant G allele may be more likely to have a severe course of AC.

Higher Levels of Serum TLR2 and TLR4 in Patients with Hashimoto's Thyroiditis.

Hashimoto's thyroiditis (HT) is an autoimmune disorder caused by the interaction between genes and environmental triggers. HT is the most common endocrine disorder, as well as the most common cause of hypothyroidism. Autoimmunity plays a crucial role in the pathogenesis of HT and recent studies suggest that Toll-like receptor (TLR) signals lead to increased inflammatory response. The aim of our study is to investigate whether TLR-2 and TLR-4 levels and gene polymorphisms contribute to the damaged immune response leading to HT. Using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, single-nucleotide polymorphisms (SNPs) of TLR2 gene Arg677Trp, Arg753Gln, 196-174 del and TLR4 gene Asp299Gly, Thr399Ile were studied in 100 patients with HT and 100 healthy controls. Also, we investigated serum levels of TLR-2 and TLR-4 in the immunopathogenesis of HT. TLR-2 and TLR-4 serum levels were found to be significantly higher in HT patients than the control group. However, no statistical significance was found between patient and control groups in terms of genotype frequencies and allele frequency distribution of TLR2 gene Arg677Trp, Arg753Gln, 196-174 del and TLR4 gene Asp299Gly, Thr399Ile polymorphisms. TLR2 gene Arg677Trp, Arg753Gln, 196-174 del and TLR4 gene Asp299Gly, Thr399Ile polymorphism do not appear to have a role in the development of HT disease. However, in our study, serum levels of TLR-2 and TLR-4 were found to be higher in HT patients than control groups. These findings suggest that TLR-2 and TLR-4 play an important role in the immunopathologic mechanism of disease by causing an increase in proinflammatory response.

TOLL LIKE RECEPTOR TYPE FOUR GENE POLYMORPHISM IN NEONATAL SEPSIS IN ZAGAZIG UNIVERSITY CHILDREN’S HOSPITAL

Introduction: The immune response constitutes the first-line defense against microbial infections. Toll like receptors (TLRs) play a fundamental role in neonatal innate immunity, and one of them, toll like receptor 4 (TLR4) is considered a major pattern recognition receptor (PRR) in recognizing lipopolysaccharide (LPS) of gram-negative bacteria. Single nucleotide polymorphisms (SNPs) among various TLR genes have been identified and maybe related to susceptibility/resistance to certain infections and other inflammatory diseases.Objective: The purpose of this study was to find a relation between sepsis-related outcomes in neonates and TLR4 Asp299Gly gene polymorphism.Method: we carried out a case control study on 72 neonates. 36 neonates with culture proven gram-negative sepsis and 36 neonates as controls. Both groups were genotyped for TLR4 Asp299Gly gene polymorphism, by polymerase chain reaction (PCR), and restriction fragment length polymorphism analysis (RFLP) by using BccI enzyme.Results: No statistically significant association between TLR4 Asp299Gly gene polymorphism and severity of neonatal sepsis (P>.99).Conclusion: TLR4 Asp299Gly gene polymorphism is not associated with increased severity of gram-negative bacterial sepsis in neonates.

GENETIC MARKERS OF IMMUNE RESPONSE DISORDERS IN WOMEN OF REPRODUCTIVE AGE WITH ACUTE PYELONEPHRITIS

Acute pyelonephritis (AP) is an inflammatory and infectious process that occurs due to immunological disorders, occurring mostly in the calyx-pelvic renal system and the tubulointerstitial zone. Pyelonephritis more often occurs in women of reproductive age.THE AIM:to study genetically determined changes in the Toll-like receptor 4, mutations in the genes of interleukin 1β, interleukin 6 in women of reproductive age with acute pyelonephritis.PATIENTS AND METHODS: The study included 26 women with acute pyelonephritis. Control group consisted of 27 practically healthy women comparable ages and without infections of kidneys and urinary tract in anamnsis. The presence of polymorphism of T (-31) C genes IL-1β, C (-174) G IL-6 and Arg299Gly TLR4 was revealed by PCR.RESULTS:Women of reproductive age with acute pyelonephritis have a high prevalence of polymorphism of IL-1β and TLR4 genes. Genotypes of TT and CT and also polymorphism of the T (-31) C gene of IL-1β and the genotype of the GG polymorphism of the gene Asp299Gly TLR-4 were associated with an increased risk of inflammatory infectious process in the kidneys. In healthy individuals, CC genotypes are found for the T (-31) C gene of IL-1β and AA for the Asp299Gly TLR4 gene.CONCLUSIONS:It is useful for women of reproductive age to provide genetic diagnostics to detect reference genes polymorphism. It will allow to reveal AP development risk group for carrying out primary prevention.

ПОЛИМОРФИЗМ ГЕНОВ TOLL-ПОДОБНЫХ РЕЦЕПТОРОВ КАК ВОЗМОЖНЫЙ ФАКТОР ПРЕДРАСПОЛОЖЕННОСТИ К РАЗВИТИЮ ТУБЕРКУЛЕЗА

The objective of the study : to detect genotypes and frequency of gene alleles of Toll-receptors (Arg753Gln – for TLR2; Phe412Leu – for TLR3; Asp299Gly – for TLR4; Ser249Pro – for TLR6) among respiratory tuberculosis patients in Zabaykalsky Kray. Subjects and methods . The distribution of genotypes of allele variants of Toll-receptors genes was analyzed in 120 respiratory tuberculosis patients and 30 healthy volunteers with a compatible gender and age distribution. Genomic DNA was isolated from leukocytes of the whole blood. In order to detect polymorphic variants of Toll-receptors genes, real-time PCR was used. The distribution of genotypes as per investigated polymorphic loci was tested for relevance using Hardy – Weinberg equilibrium. The frequency of genotype distribution in the groups was compared by Pearson's chi-square test with Yates's correction for continuity using 4-field contingency tables. The decision of the association between genotypes and the disease was made based on the value of the odds ratio with 95% of confidence intervals. Additionally, to confirm and analyze the correlation force of genotypes and development of tuberculosis based on the principle of mutual contingency, φ test (Kramer test, Chuprov test) was calculated. Results. Polymorphism of TLR2, TLR3 and TLR6 genes predispose the development of tuberculosis. The following genotypes make the biggest contribution to the formation of predisposition to tuberculosis: Asp/Asp genotype of TLR4 gene (Asp299Gly), Ser/Ser polymorphism of TLR6 gene (Ser249Pro), heterozygous Asp/Gly of TLR4 gene (Asp299Gly) and mutation Pro/Pro polymorphism of TLR6 gene (Ser249Pro). The protective effect against the development of tuberculosis is related to carriage of homozygous Arg/Arg genotype of TLR2 polymorphism, homozygous Phe/Phe genotype of TLR3 gene and heterozygous Ser/Pro polymorphism of TLR6 gene.

Toll-like receptor 4 gene Asp299Gly and Thr399Ile polymorphisms in type 2 diabetes mellitus: A meta-analysis of 15,059 subjects

AimsToll-like receptor 4 (TLR4) gene Asp299Gly and Thr399Ile polymorphisms have been reported to be associated with susceptibility to type 2 diabetes mellitus (T2DM) with inconsistent results. In an effort to clarify earlier inconclusive results, a meta-analysis evaluating the precise associations between TLR4 gene Asp299Gly and Thr399Ile polymorphisms and T2DM risk was performed. MethodsWe searched the PubMed, Embase, Web of Science, CBMdisc, CNKI, and Google Scholar until July 17, 2014. Additionally, hand searching of the references of identified articles were performed. Original observational studies dealing with the associations between TLR4 gene Asp299Gly and Thr399Ile polymorphisms and T2DM risk were selected. Heterogeneity and publication bias were determined and the meta-analysis was performed by Review Manager 5.1.4 and Stata 11.0. ResultsSeventeen articles involving 25 studies were included in the final meta-analysis, covering a total of 5963 T2DM cases and 9096 controls. For TLR4 gene Asp299Gly polymorphism, 17 studies were combined showing no evidence for association between TLR4 gene Asp299Gly polymorphism and T2DM risk. For TLR4 gene Thr399Ile polymorphism, eight studies were combined. There was also lack of evidence for significant association between TLR4 gene Thr399Ile polymorphism and T2DM risk. In addition, the similar results were obtained in the sensitivity analyses. ConclusionsThe present meta-analysis indicates that TLR4 gene Asp299Gly and Thr399Ile polymorphisms are not associated with increased T2DM risk.

Toll-like receptor 4 polymorphisms to determine acute pancreatitis susceptibility and severity: a meta-analysis.

To investigate the correlation of toll-like receptor 4 (TLR4) gene Asp299Gly and Thr399Ile polymorphisms and acute pancreatitis (AP) risk and severity. To get a more precise estimation of the relationship, a comprehensive search was performed to examine all the eligible studies of TLR4 Asp299Gly and Thr399Ile polymorphisms and AP risk. The odds ratios with 95% confidence intervals were used to assess the strength of the association. Publication bias was analyzed by Begg's funnel plots. In total, six studies with 1255 cases and 998 controls were included in this meta-analysis. Totally, no significant associations were found between TLR4 Asp299Gly or Thr399Ile polymorphisms and AP risk using five models with high homogeneity (P > 0.05). Furthermore, stratification analysis by ethnicity or assay also found no significant association in these two polymorphisms (P > 0.05), and TLR4 Asp299Gly was not associated with AP severity (P > 0.05). In addition, no publication bias was found in these studies (P > 0.05). Our current meta-analysis suggests that TLR4 Asp299Gly and Thr399Ile polymorphisms may not be risk factors to AP susceptibility.

Lack of association between toll like receptor-2 &amp; toll like receptor-4 gene polymorphisms and Iranian asthmatics risk or features

© 2014 Pourfathollah et al; licensee Herbert Publications Ltd. This is an Open Access article distributed under the terms of Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0). This permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Introduction Asthma is a complex and chronic disease in which allergeninduced inflammatory processes in the airways contribute to the development of symptoms, such as wheezing, cough, dyspnea and breathlessness [1]. Asthma is considered to be the most common chronic disease and the leading cause of hospitalization in schoolchildren [2,3]. Control of asthma and response to medication is different in patients, and different asthmatics show various levels of asthma severity and progress which would depend on multiple factors especially genetic composition of patients. The need for management of medication and control of asthma make us improve our knowledge about pathogenesis of asthma and role of different elements that contribute to airway inflammation or influence signs and symptoms [4,5]. Asthma is believed to be a complex disorder involving genetic and environmental factors [6]. Many allergens and environmental microorganisms have pattern molecules on their surfaces, and these molecules interact with pattern-recognition receptors, which are part of the innate immune system. Among the known pattern-recognition receptors for microbial products, toll-like receptors (TLRs) are an evolutionarily conserved group of molecules expressed in antigen-presenting cells and epithelial cells [7]. TLRs recognize microbial patterns and play a crucial role in linking innate and adaptive immunity inducing a proinflammatory immune response that may counterbalance allergic diathesis. They initiate intracellular signaling pathways, bind to downstream protein kinases, induce activation of transcription factors, and initiate transcription of inflammatory cytokines and other host response elements [8]. Among TLRs, TLR4 recognizes lipopolysaccharide, a cell wall component of Abstract Introduction: Asthma as chronic inflammatory airway disease is considered to be the most common chronic disease that is involving genetic and environmental factors. Toll like receptors (TLRs) and other inflammatory mediators are important in modulation of inflammation. In this study we evaluated the role of TLR2 Arg753Gln and TLR4 Asp299Gly polymorphisms in the asthma susceptibility, progress, control levels and lung functions in Iranian subjects. Methods: On 99 asthmatic patients and 120 normal subjects, TLR2 Arg753Gln and TLR4 Asp299Gly polymorphism were evaluated by PCR-RFLP method recruiting Msp1 and Nco1 restriction enzymes, respectively. IgE serum levels by ELISA technique were determined and asthma diagnosis, treatment and control levels were considered using standard schemes and criteria. Results: Our results indicated that the genotype and allele frequencies of the TLR2 Arg753Gln and TLR4 Asp299Gly polymorphisms were not significantly different between control subjects and asthmatics (p>0.05) or even in asthma features such as IgE levels, asthma history and pulmonary factors (p>0.05). Conclusions: Meanwhile some previous studies indicated TLRs and their polymorphisms role in asthma incidence and features, our data demonstrated that TLR2 Arg753Gln and TLR4 Asp299Gly gene variants were not risk factor of asthma or its features in Iranian patients. Genetic complexity, ethnicity, influence of other genes or polymorphisms may overcome these polymorphisms in our asthmatics.

Toll-like receptor 4 gene Asp299Gly polymorphism in myocardial infarction: A meta-analysis of 15,148 subjects

It remains controversial regarding the association between toll-like receptor 4 (TLR4) gene Asp299Gly (+896 A/G) polymorphism and myocardial infarction (MI) risk. Thus, a large-scale meta-analysis evaluating the potential association between this gene variant and MI risk is required. PubMed, Embase, Web of Science, CBMdisc, CNKI, and Google Scholar were searched until February 6, 2013. All the statistical tests were performed using Stata 11.0. Nine articles involving 10 studies were included in the final meta-analysis, covering a total of 8299 MI cases and 6849 controls. Overall, no significant association was found between the TLR4 gene Asp299Gly polymorphism and MI risk (G allele vs. A allele: OR=0.95, 95% CI=0.74–1.22, p=0.71; G/G vs. A/A: OR=1.03, 95% CI=0.54–1.98, p=0.93; G/G vs. A/G+A/A: OR=1.05, 95% CI=0.55–2.03, p=0.87; G/G+A/G vs. A/A: OR=0.92, 95% CI=0.75–1.13, p=0.42). In the subgroup analysis based on source of controls, there was also lack of evidence for significant association between the TLR4 gene Asp299Gly polymorphism and MI risk. In summary, the present meta-analysis indicated that the TLR4 gene Asp299Gly polymorphism was not associated with MI risk.

Genetic Polymorphism of Toll-like Receptor 4 — Predictor of Susceptibility to Recurrent Course of Chronic Pyelonephritis in Children

Objective of investigation: to study the role of Toll-like receptor 4 Asp299Gly gene polymorphism in the implementation of susceptibility to chronic pyelonephritis, to analyze its association with the major manifestations of the disease and to assess the impact on the synthesis of interleukin-6 in the blood of sick children.Methods. We examined a group of children aged 1–15 years with chronic pyelonephritis in the active stage (n = 60). Control group consisted of 95 apparently healthy people. Results. There were revealed significantly higher prevalence of Toll-like receptor 4 Asp299Gly gene polymorphism among children with chronic pyelonephritis (n = 60), identified a statistically significant correlation of mutant genotypes Asp299Gly, Gly299Gly with manifestation of the disease before the age of 3, and frequent episodes of acute respiratory viral infections, torpid urinary syndrome, unstable remission and increased secretion of interleukin-6 (p &lt; 0.001). Thus, genetically determined Toll-like receptor 4 Asp299Gly gene polymorphism is a marker of high risk of early manifestation of chronic inflammation in the kidney interstitium and prolonged recurrent clinical course of the disease in children.

Toll-like receptor 4 gene Asp299Gly polymorphism in ischemic cerebrovascular disease: a meta-analysis

Epidemiological studies have evaluated the association between Toll-like receptor 4 (TLR4) gene Asp299Gly (rs4986790) polymorphism and the risk of ischemic cerebrovascular disease, but the results are inconsistent. In an effort to clarify earlier inconclusive results, a meta-analysis was performed. We searched the PubMed, Web of Science, Embase, Cochrane database, Clinicaltrials.gov, Current Controlled Trials, CNKI, CBMdisc, Chinese Clinical Trial Registry and Google Scholar until up to 20 July 2013. Additionally, hand searching of the references of identified articles was performed. Original observational studies investigating the association between TLR4 gene Asp299Gly polymorphism and ischemic cerebrovascular disease risk were included. All statistical analyses were performed using Stata 11.0. The search strategy identified 1038 potentially relevant articles, seven of which were included in the final meta-analysis, covering a total of 1767 cases and 2785 controls. Overall, no significant association was found between TLR4 gene Asp299Gly polymorphism and ischemic cerebrovascular disease risk (for G allele versus A allele: OR = 0.95, 95% CI = 0.75–1.21, p = 0.69; for G/G+A/G versus A/A: OR = 0.96, 95% CI = 0.75–1.22, p = 0.73). In addition, the similar results were obtained in the sensitivity analysis based on studies with the high quality. In summary, the present meta-analysis indicates that TLR4 gene Asp299Gly polymorphism is not associated with increased ischemic cerebrovascular disease risk.

Interleukin-17 serum levels and TLR4 polymorphisms in ulcerative colitis.

Inflammatory bowel disease, an autoimmune disease, has two clinical manifestations including Crohn's disease and ulcerative colitis (UC). IL-17 has been the target of intensive research in autoimmune diseases. The influence of Toll like receptor 4 (TLR-4) gene polymorphisms on IL-17 production has also been revealed in UC patients and tissue inflammation in mice. To investigate the association between the TLR-4 gene polymorphisms, Asp299Gly and Thr399Ile and IL-17 serum levels with ulcerative colitis. Additionally, we aimed to study modulation effects of forenamed gene polymorphisms on IL-17 serum levels in UC patients and controls. A total of 256 healthy controls and 85 UC patients enrolled in our study. DNA was extracted and PCR-RFLP technique was employed to determine Asp299Gly and Thr399Ile polymorphisms in TLR-4 gene and IL-17 serum levels were measured by ELISA method. There was no significant difference between the frequency of Asp299Gly A>G and Thr399Ile C>T in UC patients and controls. While IL-17 serum levels in UC patients were significantly higher than controls (p=0.003), no significant difference in IL-17 levels between different genotypes existed. Additionally, a significant inverse relationship was observed between hemoglobin level and IL-17 serum levels in UC patients (p=0.039). Increased IL-17 serum levels in our UC patients might be explained through the synergistic activity of IL-17/IL-23 axis and pro-inflammatory cytokines, causing severe clinical outcome in patients with IBD. The prolonged excretion of blood in stool driven by inflammatory process which causes iron metabolism disorder and anemia may elucidate the inverse correlation between hemoglobin and IL-17 serum levels in UC patients. Lack of association between the TLR-4 gene polymorphisms and UC in our study was consistent with the results from other Caucasian populations.

No evidence for involvement of the toll-like receptor (TLR) 4 gene Asp299Gly and Thr399Ile polymorphisms in susceptibility to primary gouty arthritis

Previous studies demonstrated that toll-like receptor (TLR) 4 was involved in the development of autoinflammatory disease including gouty arthritis (GA). TLR4 functional gene Asp299Gly and Thr399Ile polymorphisms play a role in some autoinflammatory disease susceptibility. We undertook this study to analyze the association between the genetic polymorphisms within TLR4 gene and the susceptibility to GA in Chinese Han people. Two functional variants, Asp299Gly and Thr399Ile, in the TLR4 gene were genotyped using 5' exonuclease TaqMan technology from 218 male GA patients and 226 ethnically matched controls. None polymorphisms of Asp299Gly and Thr399Ile were detected in all GA cases and controls, which indicates that there is no evidence for involvement of the TLR4 gene Asp299Gly and Thr399Ile polymorphisms in susceptibility to primary GA in the Chinese Han population. Further studies with extended single nucleotide polymorphisms should be performed.

Increased NFk-B activity in HCT116 colorectal cancer cell line harboring TLR4 Asp299Gly variant.

Toll-Like Receptor 4 (TLR4), considered one of the most important TLR, recognizes lipopolysaccharide of Gram-negative bacteria. Recognition of ligands by TLRs induces signaling pathways resulting in activation of transcriptional factors such as NF-κB which are involved in the expression of inflammatory cytokines and chemokines. To prevent an inappropriate immune response, a complex network of molecules negatively regulates TLRs and their associated signaling pathways. Two cosegregating single nucleotide polymorphisms of the human TLR4 gene, namely Asp299Gly and Thr399Ile, have been associated with hyporesponsiveness to inhaled LPS. The purpose of this study was to determine the impact of TLR4 gene variant on NF-κB activity in colorectal cancer cell line. HCT116 cells were transfected with wild-type and mutants Flag-CMV1-TLR4 expression vectors. Western blot analysis was performed to evaluate selected molecules involved in TLR4 signaling. NF-κB activity was assessed by dual-luciferase reporter assay and cytokine profiles were evaluated byELISA and Cytometric Bead Array method. Results showed that the activity of pNF-κB was higher in cells harboring TLR4 D299G compared to the other cells. However, the activity of pAKT, pERK1 and pIRAK was higher in wild-type. The results of cytokine measurements showed about four fold higher level of IL-8 in cells with wild-type TLR4. This study suggest that TLR4 Asp299Gly gene variant has an impact on TLR4 signaling and potentially on intestinal homeostasis due to impaired control signals at the epithelial cell level which may lead to chronic intestinal inflammation and interrupted intestinal homeostasis and may eventually lead to colorectal cancer.

TLR2 and TLR4 gene polymorphisms in Turkish vitiligo patients

It has been shown that toll like receptors (TLR) may be involved in some inflammatory skin diseases such as psoriasis, atopic dermatitis. Vitiligo is an acquired pigmentation disorder of unknown aetiology. A number of genes playing a role in inflammatory response may be associated with development of vitiligo. To investigate whether there is an association between TLR 2 and TLR4 gene polymorphisms in Turkish patients with vitiligo. A total of 100 patients (59 women and 41 men) with vitiligo and 100 controls (58 women and 42 men) were included in the study. The TLR2 gene Arg753Gln and TLR4 gene Asp299Gly and Thr399Ile polymorphisms were genotyped by using polymerase chain reaction and restriction fragment length polymorphism method. The data were analysed by Mann-Whitney U-test, chi-squared test and logistic regression analysis. Significant difference was found in the distribution of TLR2 Arg753Gln genotype and in the allele frequencies TLR2 753Gln between vitiligo patients and healthy subjects (P < 0.05). The distribution of TLR4 Asp299Gly genotype was significantly higher in the patient group (10%) than in the control group (%2) (P < 0.05). The TLR4 Thr399Ile distribution did not show any difference in both vitiligo and healthy groups. Our findings suggest that Toll-like receptor 2 gene Arg753Gln and Toll-like receptor 4 Asp299Gly gene polymorphisms are associated with vitiligo susceptibility in Turkish patients.

Analysis of TLR4 and TLR2 polymorphisms in inflammatory bowel disease in a Guangxi Zhuang population

To study the polymorphisms of toll-like receptor 4 (TLR4) gene Asp299Gly, Thr399Ile and TLR2 gene Arg753Gln, Arg677Trp and susceptibility to inflammatory bowel disease (IBD) in the Zhuang population from Guangxi, China. A case-control study was performed from February 2007 to October 2011 which included 146 Zhuang patients with IBD in the experimental group and 164 healthy Zhuang subjects who acted as the control group. All patients and healthy subjects were from the Guangxi Zhuang Autonomous Region of China. Genomic DNA was extracted from intestinal tissue by the phenol chloroform method. TLR4 gene Asp299Gly, Thr399Ile and TLR2 gene Arg753Gln, Arg677Trp were amplified by polymerase chain reaction (PCR), and then detected by PCR-restriction fragment length polymorphism (RFLP). The TLR4 gene Asp299Gly was digested using Nco I restriction enzyme, and a single band of 249 bp was observed which showed that it was a wild type (AA). The TLR4 gene Thr399Ile was digested using Hinf Irestriction enzyme and only the wild type (CC) was detected. In addition, the TLR2 gene Arg677Trp was digested using Aci I restriction enzyme and only the wild type (CC) was detected. The TLR2 gene Arg753Gln was digested using Pst I restriction enzyme. Only the wild type (GG) as a single band of 254 bp was observed during RFLP. Overall, no heterozygous or homozygous single nucleotide polymorphism mutations were found in patients with Crohn's disease and ulcerative colitis both in the TLR4 gene Asp299Gly, Thr399Ile and the TLR2 gene Arg677Trp, Arg753Gln in the Zhuang population from the Guangxi Zhuang Autonomous Region of China. The TLR4 gene Asp299Gly, Thr399Ile and TLR2 gene Arg753Gln, Arg677Trp polymorphisms may not be associated with IBD in the Zhuang population from the Guangxi Zhuang Autonomous Region of China.

Analysis of association between TLR-4 Asp299Gly and Thr399Ile gene polymorphisms and chronic periodontitis in a sample of south Indian population

Background:To analyze the association between TLR-4 Asp299Gly and Thr399Ile gene polymorphisms and chronic periodontitis in a sample of south Indian population.Materials and Methods:Genomic DNA was obtained from peripheral blood of 60 patients with chronic periodontitis and 60 periodontally healthy subjects. TLR-4 Asp299Gly and Thr399Ile gene polymorphisms were genotyped by a polymerase chain reaction–restriction fragment length polymorphism method. The data were analyzed by a χ2-test and by relative risk estimation.Results:Thr399Ile alleles were found in 4% of chronic periodontitis patients and in 1% of periodontally healthy subjects. The prevalence of a Thr399Ile heterozygote was found to be 5% in the chronic periodontitis group and 1.67% in the periodontally healthy group, respectively. Homozygosity for TLR-4 Thr399Ile was seen in chronic periodontitis patients only, which was 1.67%. The TLR-4 Asp299Gly gene polymorphism was not detected in either chronic periodontitis or periodontally healthy groups.Conclusion:There is no significant association between TLR-4 Thr399Ile polymorphism and chronic periodontitis in a sample of south Indian population.